Brinks' Trinkets?

Just a quick question I guess!
I'm swimming in Primal Sparks and while browsing for something I could buy, I noticed that there's a nifty little trinket that increases your Piercing defense a pretty good amount for only 100 sparks. I have no other trinkets so no big deal there, but I was kind of curious to know whether or not it's really worth it? I don't really have any other purpose for these sparks, but I've only ever seen people wearing the Heart Pendant trinkets, so, yup.
I'm also curious about the elemental defense trinket but that's for 100 Forge Sparks - still a ways off from that 'un.
SO YEAH GUYS. What say you? I'm already wearing Skolver/Thorn Shield line so pierce is decent enough, but a little extra won't hurt, yeah? Or is there some kind of cap on how much I can have?

I'd rather vendor it for 10k crowns. And the elemental trinket isn't really worth it when you can make tons of money off of sunsilvers.
There doesn't seem to be a cap, you can go beyond the end of the bar with your defense. I had 100s of Primal Sparks too, so I got two of the piercing trinkets and put them on for Jelly Runs. Don't know if it makes much of a difference at all, but whatever, every little bit helps :)

Tiary - Ahah, god point there. Maybe once I get a Heart Pendant I'll do that. (Or look up the other prices of smaller trinkets and see if there's something else a little more worthwhile.)
Thanks for the input guys!
Well, the only other choice is Sleep Resist so...